Fuel cells are devices that generate electrical energy from hydrogen and oxygen and can achieve high electricity generation efficiency. The main features of fuel cells are that high electricity generation efficiency can be expected even on a small scale because electricity is directly generated without undergoing a stage of heat energy or kinetic energy unlike conventional electricity generation methods, and they have good environmental properties because of small amounts of emission of nitrogen compounds and the like and low noise and vibration. That is, fuel cells can effectively use chemical energy possessed by fuel and have environmentally friendly properties. Therefore, it is expected that fuel cells will be used as energy supply systems that will have a major role in the 21st century, and will receive attention as new promising electricity generation systems that can be used in various applications from large-scale electricity generation to small-scale electricity generation, e.g., for use in space, automobiles, and mobile devices. In order to put fuel cells into practical use, technological development is underway in earnest.
Among various types of fuel cells, a solid polymer-type fuel cell has a feature that it has a lower operating temperature and a higher power density, and in particular, in recent years, it has been expected to use it as a power source for mobile devices (e.g., mobile phones, notebook computers, PDAs, MP3 players, digital cameras, electronic dictionaries, and electronic books) and the like. As a solid polymer-type fuel cell for mobile devices, a fuel cell of flat arrangement type is known in which a plurality of unit cells are arranged in a planar manner. Regarding the fuel cell of flat arrangement type, a configuration is known in which current-collecting members for achieving conduction between electrodes (anodes and cathodes) of unit cells are disposed, not on the exposed surfaces of the electrodes, but on the periphery of the electrodes.